Hannu2

I.e. "Let's assume that known natural laws do not exist. What natural laws predict if...". So, do not expect meaningful answers if your question contains superluminal speeds or indestructible matters. Practically kinetic energy determines what happens if macroscopic piece of matter hits to Earth at relativistic velocities. Structural strength or other properties of matter are negligible in such conditions. Even very small objects can have very high energy and my guess is that effects are quite similar than nuclear explosion.

Teflon can handle somewhat more than 200 C. It or other plastics are not solution at Venus. But is dry gaseous sulfuric acid a bad problem? Probaly there is some metal which can handle it. For example common type of stainless steel 316L can handle dry HCl gas at near 1000 C. Add little water vapor and situation will be not so good. 100 bar is not very difficult pressure to handle (with simple steel or titanium sphere) and cheap large rockets we seemingly get in near future will help to solve mass issues of such pressure vessel. Electronics and electric isolation would be the worst problems. They investigate high temperature electronics made from GaN or SiC (not because Venus but to get compact power electronics with cheaper cooling systems), but I think 460 C is too much for current level. It think there is no suitable battery chemistry too and RTGs will work very poorly if cold temperature is 460 C. Do you really know that radiation level is high at Venus surface (except thermal IR due to high temperature)? It is hard to believe that any radiation from space or upper atmosphere penetrate the massive atmosphere and I also do not know any reason to expect more radioactive materials at surface than on Earth.

I am not sure how it works with steam installation but you can copy the whole normal KSP folder, rename it and get a new completely independent branch of the game. I have all versions I have played from 0.18.0.

From extreme point of view there is not more "real" things than axioms and even they are sentences generated by Stetson & Harrison method which have not yet proved to be contradictory with each other. In any case word "real" does not fit with mathematics, which is abstract logical system which have nothing to do with nature or "real world". It just happens to be suitable tool for understanding and predicting natural phenomena.

Postulates of arithmetic defines which special element of number set is additive identity. Of course it can be named with any word or symbol, but it is one unique element with special properties. Here you can find proof that if binary arithmetic operation obeys commutative law its identity element is unique. Multiplicative identity element is one and it is also unique. I think if you define operators which are not commutative, it is possible get more identity elements but your set is not anymore field and you can not use proven properties of field to handle arithmetic. But in any case I have not studied that kind of math and can not say much about it. You should also notice that + or - infinity are not elements of integer set. It seems to be quite common error. If you define such elements your set is not anymore field and will have odd arithmetic.

There is subtraction and it is defined exactly as you wrote. Subtracting is adding with additive inverse. Additive inverse is negation of the number. Zero has a special property of being additive inverse of itself. That's why a-0 = a + (-0) = a+0. Zero is also additive identity which means a+0 = a.

It may also be, that those legs are planned for landing zones or ships. They intend to use Starships as heavy satellite launcher at beginning. At least I have not read any actual plans for sending probes or other stuff to Moon or Mars with Starships and there must probably be tens of succeeded flights before man rating and manned version. I think they will make heavier off road legs for later versions when they get contract to bring something beyond Earth orbit.

Yes, in real life they use engineer workyears to take photographs and make detailed topographic models from every considered landing zone before trying actual landing. Those modern spacecrafts are intended to make pinpoint landings with accuracy of few meters or even less if they send navigation beacons beforehand.

It has been, but recent development has decreased cost of dv (=mass to orbit) and that trend seems to continue when SpaceX and Blue Origin get next generation rockets ready. Launch is not any more biggest cost of satellite or probe and when next generation manned ships come int action it is probably not highest cost in manned operations anymore. Cost of life support and (in my opinion too) high safety expectations develop much slower rate than cost of brute force.

I have read that stars are light emitting huge objects at crazy distances. That book told also, that one of them are very much closer than others and understood that it is visually very noticeable in those southern countries where thick cloud layers does not always block visibility, especially when something interesting happens on sky. One friend traveled once to Spain and saw it. It was very nice, light, warm, etc. Astrophysicists call it "Sun". Greetings from Finland.

It is hard to believe that they could avoid hitting each other violently during supersonic atmospheric flight. But maybe they could have a hinge which opens at fairing jettison and closes before hitting atmosphere. But there would be risks. I think one failure of telecom satellite or other expensive payload due to fairing separation problem would ruin all possible savings for a lifetime of launcher system.

Technology is not adequate for development of space exploration. Many very nice things would be possible in two decades, if we did not have stupid political and economical restrictions. If states and/or billionaires would invest much money (kings and wealthy people have built monuments during whole history of mankind except about last century and science and technology could be monuments of modern industrial civilisation), all possible technologies (for example nuclear propulsion and dangerous experiments of hibernation) would be used and safety regulations would be lowered to level it was in golden era explorations (men was cheap and nobody cared deaths). But it is not true and political and cultural attitudes are much slower and harder to overcome than technical problems. For example I do not believe that nuclear technology is not allowed to use in next couple of generations (i.e. in foreseeable future). It is just too scary for average taxpayer.

I did not say that one is evil and one is good. US government had some reasons to use shuttle despite its costs and safety issues but I do not believe that such reasons to use SLS will ever exist. Politicians can not continue expensive and non productive project forever if there will be similar or even larger commercial products at orders of magnitude lower cost. I think continuous chain of delays serve better real objectives of SLS than actual attempt to fly. If it fails it is game over immediately and if it works it is too expensive for operational use. But they can always announce delay of year or two and hope that politicians delay their decision to end project and give couple of billions more.

Shuttle was active about 30 years and flew more than 100 missions. It is impossible to even imagine as great success for SLS. I am surprised if it fly ever. It seems to be some kind of political support operation for certain industry.

I have played couple of days and at it seems to work. At least basic functions, I have not tested all things I never use.

I can not decide between sample return from Mars or Cassini like heavy and versatile orbiter to Uranus or Neptunus. Both of them would be hyperinteresting for me. I think those would be possible in my lifetime (expectation value is about 40 years), with some luck both of them. I prefer hard science over manned propaganda tricks. Exploration of Europa's ocean would be of course on my favorite list too, but I do not see it realistic if ice cover is several tens of kilometers thick. Piercing through the ice, operation at huge pressure, communication with surface station etc. are quite nasty problems which would need decades of development time and more funding which is realistic to expect for space science, especially if politicians prefer manned operations on Moon during next decades.

I have heard that Elon's version does not yet have even operational F5/F9. I think he would pay nice amount of money for that function.

It is the most expensive (in dv) place to go with huge difference to any other celestial body in our Solar system. It is also far cheaper to launch spacecraft out of Solar system than brake it on orbit around Mercury. Mercury probes have been small and used very complex trajectories with lot of gravity slingshot flybys of Venus and Mercury. Those metals are much easier to get from metal asteroids. They have much higher concentrations, much lower gravities and not extreme level of solar radiation, which does not make energy production cheap and easy.

There are ionic fluids which have very low vapor pressures. However, I have no idea how corrosive they are or is there other problems with spacecrafts diving in them. But in fictive story there can always be assumptions that "this special material can hadle that liquid" Also, I do not know would it be more practical to use exotic chemicals or more common, like water or ethanol, and accept some evaporation losses during use. In any case such liquid air lock sounds very fictive and not practical at all. https://en.wikipedia.org/wiki/Ionic_liquid

I would use some other word than easily. At least it you include begging of funding. How much polar bear union paid for you? That penguin "rescue" operation would mean few easy years for bears. My choise would depend on tech level and funding. There are no techical or scientific reasons to send humans anywhere. I would probably prefer better research stations on Mars and Moon, but if politicians wanted and payed propaganda tricks, a visit on Kallisto would be nice and prestige. Especially if they gave a license to develop and use nuclear propulsion technology too. Asteroids would be so boring places and it is not very realistic to assume radiation shielding for manned operations on inner Jovian moons.

Argon compounds are very unstable. Single molecules are formed in solid matrix of noble gas at cryogenic temperatures and can be investigated with spectroscopical methods. Production and storage of macroscopic quantities is impossible. https://en.wikipedia.org/wiki/Matrix_isolation It seems that absurd level of pressure increase stability of some light noble gas compounds, but those conditions are far beyond laboratory experiments. Also, Helium hydride ions can be formed in interstellar gas clouds and have been recently detected,. https://www.nature.com/articles/s41586-019-1090-x

Your mileage may vary. I bought "simple" and "slow" RC-aircraft to my daughter and I have to say that it is crazy hard compared to RC car, which is probably much harder to drive that very slow all wheel driving rover. I hope that there are dead calm weathers at Titan during the mission. I have also had a coaxial helicopter and based on my experience I am happy that my job is not to program automatic flight algorithm for use in conditions turning flipped helicopter (and changing of rotor blades) costs billions and take decades.

It may be, but helicopter must choose landing site fully autonomously. There will be no orbiting probes to survey good landing sites (or is it included in mission) and no time to wait instructions from Earth. I am quite sure, that RTG does not produce even near enough energy for continuous flying. They must load batteries slowly and then they can fly a short trip. That will be very interesting project. Real science and not manned circus tricks which are now so fashionable. I really hope that it will success in my lifetime.

As many already wrote, certainly it would be possible if devs wanted it. But practically it would be extremely laborious work and change the nature of the game significantly towards real exploring. Entertaining exploration of planet sized objects would probably be very hard to balance. I would like to idea, but I think most of the players like more to have known world and devs have no motivation to it. It would be excellent idea for a new game (not economically, though). Procedurally generated really 3D modeled planets, also non spherical, realistic gravity modeling between bodies and ships (i.e. no stable orbits) and much research and exploration on different conditions combined to KSP style ship building. It could be more severe engineering style quasirealistic game for engineers and tech students.

Everything was great but then some boring funkiller invented so called safety regulations and bye bye OF2.